Improvement in kilns for calcining ores, limestone



UNITED STATES PATENT GEEICE.

oHAELEswILLIAM SIEMENS, or WEsTMINsTEE, ENGLAND.

.IMPROVEMENT `IN KILNS FOR CALCINING ORES, LIMESTQNE, 86C.

' Specification forming part of Letters Patent No. 104,655, datedJune2l, 1870.

To uf/ZZ whom it may concern,.-

Beit known that I, CHARLES WILLIAM SIE- MENS, of Westminster, of thecounty of MiddleseX, England, have invented" an4 Improves ment in Kilnsfor Calcining Ores, Limestone,

or other Matters; and I dohereby declare the same to be fully describedin the following specification and represented in the accompanyingdrawings, of Which- Figure l denotes a vertical section of it, suchsection being taken on the line X X of Fig. 3.

lFig. 2 is a sectional plan on lines Y Y and y y of Fig. 1. Fig. 3 is asectional plan on lines The kiln I employ for calcining the spathic oreor lime to be used is not dissimilar in general form and arrangementfrom an ordinary limekiln; but the material to be calcined is charged atthe top without the admixture of solid fuel. Gaseous fuel is to beadmitted at the circumference of the kiln at some elevation from thebase, and also in the center of i the kiln, through an ascending channeland under a covering hood. Atmospheric air enters among the calcined andheated mass through the discharge-openings at the bottom of the kiln,and, after having become heated itself, meets With thedivided currentsof gaseous fuel, with' which it enters into complete combustion,producing intenseheat. Theproducts of combustion, together with theliberf ated carbonic acid and aqueous vapor, rising through thesuperincumbent mass of materials, heat the same, preparatory to itsbeing acted upon by the calcining-heat, and escape at the topcomparatively cool from the freshlycharged materials. u

Oneadvantage of this calcining-kiln is that the products of combustionescape from it in L the form of carbonio acid instead of carbonio oxide,with their admiXture of nitrogen, resulting ina great saving of fuel.Another advantage consists in the absence of ashes of the combustiblematter employed, and another in the regular` and intensified actionwhich can be obtained in regulating the supply of gas to the continuousaction of the kiln. A gallery or galleries are erected on the outside ofthe kiln, and stoppered apertures are provided through its side wallsfor the purpose of introducing tools for prizing the material incase itshould hold together and not descend freely. The current of air vand gasthrough the calcining mass may be accelerated by placing a hood orchimney upon the kiln, and by introducing a steam-j et into the same.Kilns of this description may be used generally with advantage incalcining ores and for' burning lime, cement, and plaster-of-paris.

The. kiln A is provided 'with aiming of V fire brick, as shown, and atitsbase a conical projection, B, through the center of which is formedthe passage C for combustible gas,` which is "to be supposed to besupplied from one or more gas-generators, and to pass through the flue Dand issue into the kiln from beneath an riron hood, E, arranged over thecon'e B. At the same time combustible gasl is also to be caused to passfrom the flue D through a circharge-apertures K at bottom will, inrising.

up through the heated calcined masses, take up heat therefrom, and, incoming into contact with the combustible gas issuing from thehood-Irland through the opening H, will enter into combustion with thegas, so as to effect a considerable and equable'heating of the entirecharge without any admixture of solid fuel being requisite. `The supplyof gas through the apertures H at the circumference may be regulated bymeans of a damper, L, in t e conv duit G.' The hot gaseous products ofcombustion, in passing up through the kiln, impart their heat to thecharge in the upper part-before escaping from the top.

rIo prevent the clogging of the charge of the kiln stoppered apertures MM N Nare formed around the kiln, so as to be accessible from a gallery,0, arranged as'shown in Fig.'3.

Through these apertures tools may be introduced for prizing the chargeand causing it to descend freely. Access may be had to the passages Gfrom the gallery O, (through apertures P, provided with'covers,) for thepurpose of clearing them out when necessary. Other apertures, R,provided with doors, may also be formed at the bottom of thesegas-passages,

they being accessible from a pit, S. The disi charge-openings K shouldbe provided with doors Q, to regulate the draft of air and the dischargeof the eoloined materials.

I claim- The arrangement and combination of the cone B, its hood E, andthe system of air and gas ues C D F G, with the kiln, constructedsubstantially as specified, the Whole being to operate as and for thepurpose as explained.

Vitnesses: C. WM. SIEMENS.

Rona?. LINKsoN, EDWD. N. HoBBs,

Both 0j' 2 Popes Head Alley,

Oorfnhz'll, London, Gents.

